3-D power Doppler ultrasound: New possibilities in diagnosis and documentation of tumors of the base of the tongue.

Background: To evaluate a novel 3-D power Doppler ultrasound technique (3-D PDUS) in the diagnosis and documentation of tumors of the base of the tong ue. Patients and Methods: Twenty patients with tumors of the base of the to ngue (2 T1, 6 T2, 6 T3, and 6 T4 carcinomas) prospectively underwent two-di mensional gray scale and power Doppler ultrasound and 3-D PDUS (3-Scape(TM) ). All examinations were per formed with a 7.5 MHz transducer and the Sonol ine Elegra Advanced. Two independent observers compared the examinations re garding clear tumor margins, maximal diameter of the tumor, midline crossin g, infiltration of the mylohyoid muscle, infrahyoidal tumor, contact to the lingual artery, vascularization in the tumor and in surrounding tissue, an d evaluated the documentary use of the 3-D reconstruction. Results: All rel evant pretreatment parameters were accessible in the 3-D data; results of b oth observers were almost identical. An acquisition and reconstruction of t he 3-D data takes only a couple of minutes. In addition to two-dimensional ultrasound 3-D PDUS allows reconstruction of axial images of the base of th e tongue similar to CT images and a 3-D visualization of tumor vascularizat ion. Conclusions: 3-Scape is a novel user-friendly method that allows unint errupted acquisition of large 3-D volumes, and digital storage and transmis sion of ultrasound studies without loss of information. US images can be re constructed in any desired plane or visualized in 3-D. In the future, addit ional software will permit exact determination of the volume and deg ree of vascularization of tumors.